Specifically, the invention relates to an apparatus of the type described in U.S. Pat. No. 2,800,949, that is, an apparatus for balancing at least one person in a plane substantially parallel to the ground, essentially by the force of the action on a control device by the feet of the person.
In addition to a fixed support such as an overhead suspension framework, an apparatus of this type includes:
at least one seat supported by a beam located approximately parallel to the seat; PA1 at least two rigid suspension members, which are connected, substantially parallel to one another, by pivotal connection to the fixed support and to the beam in such a manner as to constitute a parallelogram of elements, which is deformable in the plane perpendicular to the ground, known as the balancing plane. PA1 each seat that faces a suspension member is located on the beam at a distance from the axis by which the beam is pivotally connected to the closest suspension means, approximately the distance between the seat and the pivot axis of the knees of a majority of users of the apparatus when they are seated on the seat in question, and PA1 the aforementioned suspension members extend below the plane of the seat so that, in a position of equilibrium of the apparatus, it has a footrest for the feet of the user located substantially vertically downward of the aforementioned pivotal connection. PA1 first, instead of being carried by the suspension means closest to each seat, an extension having the footrest for the feet of the user on the seat is carried by the suspension means farthest away from that seat, and PA1 second, the extension of the suspension means is arranged in such a manner that, in a position of equilibrium of the apparatus, despite its connection to a suspension means remote from the seat in question, the footrest for the feet of the user is located vertically below the pivotal connection means for the suspension means closest to the seat in question.
In this apparatus:
In this way, the user can generate and/or maintain the balance sought of the seat, and then slow down the motion, solely by the controlled use of his legs.
Only the part of the lower limbs of the human extending from the knee to the foot is involved in a practical sense in this action.
Although the apparatus with pendulum motion of the type described above properly functions, nevertheless, the apparatus does not allow the user to efficiently develop a thrusting action of his entire lower limbs.